A female cat's first heat: when it comes, how to recognise it and what to do
The first time, many owners think their cat is ill or in pain: she rolls around, yowls as if crying and drags herself across the floor. It is heat, and in cats it works very differently from dogs. It is worth understanding, because it comes back far more often than you would imagine.
When it starts
Most female cats have their first heat between five and nine months, although some have it at four and others not until a year. Breed plays a part (Oriental breeds such as the Siamese tend to be early; Persians, later), as does weight and, above all, light. The cat is a seasonal breeder triggered by long days: her cycle switches on when there are more than about twelve hours of daylight. In Spain that means the main season runs roughly from late winter to early autumn. A kitten born in autumn may not have her first heat until the following spring; one who turns five months in April may have it straight away. Indoor cats with many hours of artificial light can cycle almost all year round.
How to recognise it: no bleeding
Unlike a bitch, a cat in heat usually does not bleed or have any visible discharge, so heat is recognised by behaviour. Loud, insistent, plaintive yowling, sometimes all night. She rubs against everything: legs, furniture, corners. She rolls on the floor, drags herself along, is much more affectionate than usual or, the opposite, restless. If you stroke her back, she raises her rear, moves her tail to one side and treads with her back legs: this is the mating posture, lordosis. Some spray urine, eat less and try to get out through any gap. All this is often mistaken for pain, but a cat in heat is not ill: she is looking for a male with all her might.
How long it lasts and how often it returns
The heat itself lasts on average about six or seven days, although it can range from two days to almost three weeks. What surprises people is what happens next. Cats are induced ovulators: they need mating to ovulate. If there is no male, she does not ovulate, the cycle does not close and two or three weeks later she comes into heat again. During the light season, an entire, unmated female can spend more time in heat than out of it, month after month. It is not that it will pass: the cycle is designed to repeat until she becomes pregnant or the short days arrive. That is why waiting "to see if she calms down" rarely works.
The real risk: pregnant in minutes
A cat in heat will do the impossible to get out, and an entire tom will smell her from a long way off. One careless moment with a window or the balcony door is enough for her to come back pregnant, and mating is so quick there is no time to step in. Pregnancy lasts about two months and litters are usually three to five kittens. What is more, she can come into heat again a few weeks after giving birth, even while nursing. It is also not unusual for one litter to have several fathers. If you have an entire female and an entire male at home, even if they are siblings, pregnancy is only a matter of time. And bear in mind that open windows during heat are also a typical cause of falls.
What to do while it lasts
Patience, doors and windows closed or screened, and distraction. It helps to play with her with a wand toy several times a day so she burns off energy, offer her a warm, quiet spot, keep to routines and not scold her, because she cannot help it. A warm blanket or a wrapped hot water bottle calms some cats. Facial pheromone diffusers may reduce stress a little, although they do not stop the heat. What you should not do is try to "get rid of it" with home remedies or tablets bought without a prescription: there is no household trick that stops the cycle. If the yowling is driving you to despair, remember that she is having a hard time too, and that a permanent solution exists.
The heat pill: why not
For years, progestogens in tablet or injection form were used to delay or stop heat, and some people still recommend them. Feline vets advise against them for long-term use because of their well-documented side effects: mammary hyperplasia and tumours, pyometra, diabetes, weight gain and behaviour changes. A single dose is not usually a disaster, but stringing them together for years is one of the causes of mammary tumours in young female cats. If for a specific reason she cannot be spayed for now, talk to your vet about current alternatives and their risks. For a pet cat, the sensible answer is spaying.
Spaying: best before the first heat
Today the recommendation is to spay at around four or five months, before the first heat, and in Spain Law 7/2023 requires cats to be neutered before six months except for registered breeders. Spaying before the first heat gives maximum protection against mammary tumours, which in female cats are malignant in the vast majority of cases. Letting her have one heat "so she develops" or one litter "so she is happy" has no basis at all: it adds nothing to her health or her character. If she has already had her first heat, it does not matter: she is spayed anyway, the sooner the better, ideally between one heat and the next.
When heat is not normal
See the vet if she bleeds or has discharge from the vulva, especially if it smells bad or looks like pus, if she drinks and urinates much more than usual, if her belly is swollen, she is lethargic or stops eating: in an entire female, and more so if she has been given progestogens, it could be pyometra, an infection of the womb that is a surgical emergency. It is also worth seeing the vet if a spayed cat shows signs of heat again: a piece of working ovary may have been left behind, known as ovarian remnant syndrome, which is diagnosed with hormone tests or ultrasound and resolved with a second operation.
What if I want her to have kittens?
Before deciding, think about what it means: finding several responsible, committed homes for each litter, in a country where rescues are permanently full of kittens every spring. Breeding also requires prior health checks, FeLV and FIV testing, worming, vaccinations for the kittens, a possibly complicated birth and the emergency caesarean that sometimes comes with it, and meeting the legal obligations for breeding. Breeding pedigree cats has its own register and requirements in Spain. If what you want is the experience of watching kittens grow up, fostering for a rescue gives you that without adding more cats to the world.
A cat in heat does not bleed; she yowls, rolls around and repeats the cycle every few weeks while there is daylight and no mating. Pills are not the answer because of their effects on the mammary glands and womb: the recommended option is spaying at around four or five months, before the first heat.
Educational content from Michipedia, translated from the Spanish original. It does not replace the advice of a vet or a feline behaviour specialist. Every cat is an individual.